Hello everyone! We recently purchased a truck and plow set up and are having a issue with the plow. When we run the plow, it operates just fine, but after about 5-10 minutes of moving, it stops. It does not do it in one position, it can be in any position at the time it stops working. After you let it sit for a while, it will start working again, but only for a short amount of time before it stops again.

The plow is a 9ft pro-plus, ultramount, around the year 2004-2006. We have hooked it up to another truck and it does the same thing on it, so it is somewhere on the plow side. We have flushed the system once and cleaned the filter, which the fluid was pretty dirty.

We have had a shop look it over and they replaced a spring in one of the check valves, but that has not solved the problem.

"Stops working" is pretty vauge. Does it go completly dead or does it make noise but just not move? Does the controller light go out? You need to narrow the symptoms down a bit for us to help. If it goes completly dead and you have to turn the controller on again every time it stops then it is probably a bad grill plug, loose ignition feed or a bad ground.

__________________
Apto Quod Victum "Adapt and overcome"

Western factory trained installer / mechanic.
Used to own and run plows, now I just install & fix them...

When the plow stops working, it makes a ticking sound at the motor, similar to what the solenoid sounds like when the plow is operational. The light on the controller stays on, and all other electronics stay on as well.

We did take the motor off the plow yesterday and we are having someone look at it. There was a lot of metallic dust that came out of the motor when we took it off, so it may be the problem.

If nothing obvious is found wrong with the motor I would try putting a test light across the motor terminals to see if power continues to be fed to the motor when this failure happens. But this does sound like a motor failure especially when you say you have metal fileings in it.

__________________
Apto Quod Victum "Adapt and overcome"

Western factory trained installer / mechanic.
Used to own and run plows, now I just install & fix them...

OK, so we replaced the motor today and the plow is still acting up. It will run for a while, but stops working. When we replaced the motor, we cleaned all the electrical connections and we also replaced the coils as well, since we had 3 new one's on hand. The plow will run for a short period of time, but it will stop and the only thing you hear when you push on the controller is a ticking at the pump, where the coils and cartridges are. We have cleaned and inspected the pick up tube and filter as well.

One thing I find strange when it does run is that when you move the plow to the left, it moves faster than if you move it to the right. The motor also makes a slightly different noise going that direction as well. The other ultramount plow we have does not make a different noise and it also does not make a ticking sound at the pump.

I'm just wondering if the cartridges at the pump are causing my problem? Seams like I have chased the problem to this area, but i am not familiar with how the cartridges work, so I am stuck. Is there something mechanical inside the cartridge that could go bad and cause the plow to lock up periodically?

ok, if I'm getting you right, every time that it stops working the motor is not spinning, correct?

then the problem can't be cartridges, coils, oil, filter or any of that. The motor has to run. Since you said it had crap in the motor, I would think that would be the problem, but now since you have a new motor on it and you have the same intermittent problem, then I'd think maybe controller is getting flaky or the grill connector. or maybe even loose connection in the battery cables somewhere?

From what I am reading the motor stops and there is a clicking from the motor... If this was a valve problem the motor would still run and if the valves were not directing the fluid somewhere the pressure would just go over the pressure relief valve. Are you sure the clicking is coming from the motor and not from the valves or the main motor relay? I would be going back to the test light across the motor terminals. You need to see if the motor is being fed continuous, reliable power or if it is a feed problem.

__________________
Apto Quod Victum "Adapt and overcome"

Western factory trained installer / mechanic.
Used to own and run plows, now I just install & fix them...

Thanks for the input guys. This morning, we cleaned all the connections again and even swapped in a new solenoid, just to cover the bases. We ran the plow and it has continuous power up until it starts to 'act up', which it does not have power at that time. When the plow tries to move, you can hear a tick around the area where the motor meets the pump housing. After a few attempts, it will start working again but then stop again.

The motor gets warm when doing this, not hot to where you cannot touch, but abnormally warm. We have another ultramount in the fleet and it does not get as warm as this one and it runs smooth in all directions. The one we are having a problem with seems to 'strain' going to the left. It also always quits when the plow is angled all the way to the right and you try to go back to the left.

We even removed the plow side and truck side power supply and used jumper cables to rule out a bad connection on the plugs, but it does the same thing. We also tried a different controller, but with the same results.

I would if it was a 3-plug instead of a a 2-plug set up and all our other plows are unimounts. I guess I could swap out the truck side power supply and rule that out; however, I figure that I did that by running jumper cables from the solenoid to the pump directly. After doing that, it still was acting up.

This afternoon we pulled the valve/cartridge from the good plow and swapped it with the broken plow just to rule that out as well. Same problem......I am wondering if the relief valves or pilot check valves are having anything to do with this? The bypass check valve was just replaced right after we bought it because during inspection of the plow after we bought it, there was a small ball or spring missing that was supposed to be inside.

Sorry just assumed and I shouldn't have! When you said it stopped working and there was a problem with the relief that should be two different things. Power to the motor makes it spin regardless of the relief valves. when it stops there might be some resistance some where and it heats up and causes the stopping.

It definitely has some resistance when moving the plow to the left, which is why I am thinking it is something in the pump. Don't know why it would stop the motor, but on the electrical side everything is clean and has been tested/checked.

The ground is good, it has been checked and cleaned several times. The plow side has a new power/ground harness and the truck side is clean. I am going to swap the truck side with the other ultramount we have tomorrow, just to rule it out.

I will test the solenoid and signal power this afternoon. I will also check the wiring as well since this was a truck bought with the plow on it already, there may be a wiring mix up at the solenoid. Thanks for your help.

Ok, we tested the solenoid and when the plow stops working, it has power from the controller to the solenoid (signal power) and power running from the battery to the solenoid, but no power going out. I would think this is a bad solenoid, but this is the second one that we have tried and the other one was doing the same thing. Could it be possible that the solenoid is bad? If so, then that is two brand new 'lemon' solenoids that we have replaced.

Another interesting note, when the plow stops moving sometimes the motor runs and the plow does not move. Most of the time, when the plow stops, the motor will not run either when you push left or right on the controller.